Novel 16-alkylene steroids and processes



United States Patent Olfice 3,418,316 Patented Dec. 24, 1968 3,418,316 NOVEL 16-ALKYLENE STEROH)S AND PROCESSES David Taub, Metuchen, Norman L. Wendler, Summit, and Harry L. Slates, Madison, NJ., assignors to Merck & Co., Inc., Rahway, NJ., a corporation of New Jersey No Drawing. Original application Mar. 19, 1958, Ser. No. 722,390. Divided and this application Mar. 1, 1960, Ser. No. 11,984

1 Claim. (Cl. 260-2395) CHaOR' where R is alkyl, R is hydrogen or acyl, R is hydroxy or oxygen, and X is hydrogen or halogen. The broken line between carbon atoms 1 and 2 indicates that a double bond may be present in this position.

The 16/8-alkyl steroids produced in accordance with the present invention possess extremely high anti-inflammatory activity, considerably greater than that of the parent steroids, and are especially effective for the treatment of arthritis and related diseases since they can be administered for their cortisone-like action in extremely low dosage thereby minimizing undesired side effects. The activity of 16 beta-alkyl steroids is especially novel as all previous group substitution modifications of cortical steroids which have resulted in increased anti-inflammatory activity have involved introduction of alphasubstituents.

In preparing our novel chemical compounds, the starting material utilized may be a 3-substituted-l1-oxygenated-16-pregnene20-one or 3-substituted-1l-oxygenated- 16-allopregnene-20-one which may be identified by the following structural formula wherein X is hydrogen or halogen, Y is alpha or beta hydrogen, Z is oxygen, dioxolane, alpha or beta acyloxy or hydroxy, and R" is hydroxy or oxygen as above, with or without a double bond at the 5(6)-position.

In a preferred embodiment of our invention, 3a-acetoxy-16-pregnene-l 1,20-dione which is represented by the following formula is utilized as the starting material. However, it is clear to those skilled in the art that other starting materials, such as those described above, may be similarly converted to the desired end products.

It has been found that 3oc-acetoxy-16-pregnene-11,20- dione may be caused to react with diazoalkanes, such as diazomethane and diazoethane to form 3a-acetoxy-16a, l7a-alkyleneazopregnane-11,20-dione which has the following structural formula wherein R is hydrogen or alkyl.

Upon heating 3a-acetoxy-16a,l7a-alkyleneazopregnane-11,20-dione, there is formed primarily 3a-acetoxy- 16-a1kyl-16-pregnene-11,20-dione which may be represented by the following formula a to wherein R is alkyl as above.

Heating 3a-acetoxy-16m,17a-alky1eneazopregnane-l1,20- dione also results in the formation of a small quantity of each of the two corresponding isomeric forms namely, the cyclopropane, 3-acetoxy-16a,17a-alkylenepregnane- 11,20-dione, which has the following structural formula 3 wherein R' is hydrogen or alkyl and exocyclic olefin, 3-acetoxy-16-alkylene-pregnane-11,20-dione, which may be represented by the formula i C=O RII/ AcO- where R is hydrogen or alkyl as above.

Treatment of the above isomeric form, namely the 3- acetoxy-l6-alkylenepregnane-l1,20-dione with an alkali hydroxide yields 16-alkyl-3a-hydroxy-16-pregnene-l1,20- dione which has the formula wherein R is alkyl.

Oxidation of 3ot-acetoxy-16-alkyl-16-pregnene-11,20-dione, the major isomer obtained above, with an oxidizing agent such as hydrogen peroxide in the presence of sodium hydroxide or peracids such as peroxytrifiuoraoetic acid results in the formation of 16fl-alkyl-16u,17a-epoxy- 3u-'hydroxypregnane-11,20-dione which has the structural formula wherein R is as above.

Upon treatment of 16fi-alkyl-l6u,17a-epoxy 3a hydroxypregnane-11,20-dione with a strong acid such as perchloric acid there is formed an olefin mixture of 16- alkyl-Sa,17a-dihydroxy-l5-pregnene-11,20-dione and 16- alkylene-3a,17a-dihydroxy-pregnane 11,20 dione which may be represented as follows '--0H 011 0 In 0- and HO-- HO-- wherein R' is hydrogen or alkyl and R is as above.

Treatment of the mixture of 16-alkyl-3a,17u-dihydroxy-lS-pregnene-l1,20-dione and 16-alkylene-3a,17adihydroxypregnane-l1,20-dione successively with lithium aluminum hydride and sodium metaperiodate results in a mixture of the endocyclic 16-alkyl-3a,1IB-dihydroxy-lS- etiocholene-17 one and the exocyclic, 16-alkylene-3a,1lfi dihydroxyetiocholane-l7-one having the structural formula wherein R' is hydrogen or alkyl and R is alkyl as above.

Upon treatment of 16fi-alkyl-16u,17u-epoxy-3a-hydroxypregnane-11,20-dione with hydrogne bromide in acetic acid there is formed 3u-acetoxy-16-alkylene-17u-hydroxy-pregnane-l1,20-dione, uncontaminated with the 15- pregnene isomer. There is also produced 3a-acet0xy-16- alkyl-15-bromo-16-pregnene-11,20-dione which may be represented by the following formula MQQ where R is alkyl. The 3m-acetoxy-16-alkyl-15-bromo-16- pregnene-11,20-dione thus produced is an important intermediate in the preparation of other active steroids.

The 3a-acetoxy-16-alkyl-15-bromo-16-pregnene-11,20- dione may be reacted with pyridine to form 3a-acetoxy- 16-alkyl-14,l6 pregnadiene 11,20-dione which has the formula where R is as above.

Alternatively, hydrogenation of 16,8 alkyl 16oc,17a.- epoxy-3u-hydroxypregnane-l1,20-dione under acidic conditions produces directly the above mixture of 16a-alkyl- 1 o I HO-- 110-- wherein R is as above.

The above epimeric mixture of 16a-alkyl-21-bromo-3u, 17a dihydroxypregnane 11,20 dione and 165-a1kyl-21- bromo 3a,17a dihydroxypregnane-l1,20-dione may be reacted with potassium acetate to form an epimeric mixture of 16a alkyl 3a,17,a,21-trihydroxypregnane-11,20- dione 21-acetate and 16fi-alkyl-3a-17a,21-trihydroxypregname-11,20-dione ZI-acetate which may be represented by the following formulae CHzOAc CHzOAc I 1w 9% J\ "25 l IQ l O l 1 HOFC and HOUC wherein R is as above.

The above epimerie mixture may be separated by chromatography or crystallization at this stage or carried further.

Reaction of a mixture of 16a-alkyl-3a,17a,21-trihy droxy-pregnane-l1,20-dione 21-acetate and 16,8-alkyl-3a, 17a,2l-trihydroxypregnane-l1,20-dione 2l-acetate with an oxidizing agent such as n-bromosuccinimide or chro mic acid results in the formation of a mixture of 160calkyl 170:,21 dihydroxypregnane-3,l1,20-trione 2l-acetate and 16,8-alkyl-170:,21-dihydroxypregnane-3,11,20- trione 21-acetate which have the following structural formulae CHzOAc wherein R is as above.

, The mixture of 16a-alkyl 17u,2l-dihydroxypregnane- 3,11,20-trione 21-acetate and 16,8-alky1-17a,2l-dihydroxyand pregnane-3,ll,20-trione 21-acetate can be by chromatographic procedures.

The alkyl-17a,2l-dihydroxypregnane-3,11,20-trione Zl-acetate is reacted with bromine to form 16,8-alkyl- 4 bromo :,21-dihydroxypregnane-3,l1,20-trione 21- acetate which has the following structural formula separated $H2OA0 0 0 wherein R is alkyl.

The 165 alkyl-4-bromo-17a,2I-dihydroxypregnane-B, 11,20-trione 21-acetate obtained above is then reacted with a slurry of semicarbazide hydrochloride and sodium bicarbonate to form the 3-semicarbazone of 16/8-alkyl- 1711,21 dihydroxy-4-pregnene-3,11,20-trione 2l-acetate which may be represented by the following structural formula wherein R is as above.

The above 3-semoicarbazone of 16flalkyl-17a,21-dihydroxy-4-pregnene-3,11,20-trione 21-acetate is then reacted with, for example, pyruvic acid in aqueous acetic acid to form 16/3-alkyl-17a,21-dihydroxy-4-pregnene-3, 11,20-trione 21-acetate having the following structural formula (llHzOAc C=O wherein R is as above.

The above compound may also be named 16,8-alkylcortisone acetate, one of our active end products which possesses efiective anti-inflammatory activity.

It has been found that the 16/3-alky1-17a,2l-dihydroxy- 4-pregnene-3,11,20-trione 21-acetate may be converted to the corresponding 21-01, namely, l6fl-alkyl 17a,21-dihydroxy-4-pregnene-3,11,20-trione, by reaction with potassium bicarbonate in aqueous methanol. The latter compound is then reacted with semicarbazide hydrochloride in the presence of dimethylformamide to form the 3,20- disemicarbazone of 16,B-alkyl-17a,21-dihydroxy-4-preg- 7 nene-3,ll,20-trione which has the following structural formula wherein R is alkyl as above.

Reduction of the 3,20-disemicarbazone of l6B-alkyl- 1711,21-dihydroXy-4-pregnene-3,l1,20-trione with sodium boronhydride produces the 3,20-disemicarbazone of 16,8- alkyl-l15,17a,2l-trihydroXy-4-pregnene-3,20-dione, which has the following formula:

omor'r C=NNHC ONE:

wherein R is as above.

The 3,20-disemicarbazone of 16,8-alkyl-llfi,17a,2l-trihydroXy-4-pregnene-3,20-dione is reacted with pyruvic acid in aqueous acetic acid to remove the semicarbazone groups at the 3 and -positions to form 16,8-alkyl-llfl, 170:,21-trihydroxy-4-pregnene3,20-dione which may be chemically represented as follows:

onion o=o L--OH HO R CH2 OAC wherein R is as above.

Other 2l-acylates may be prepared by reacting the 21- alcohol with the appropriate acyl anhydrides.

By reacting 16B alkyl l1,8,l7a,2l trihydroxy-4-pregnene-3,20-dione Ill-acetate with methanesulfonyl chloride in dimethylformamide there is formed l6B-alkyl-l7a,2l-

8 dihydroxy 4,9(11) pregnadiene 3,20 dione 2l-acetate of the following structural formula $H2OA0 o 0 I In wherein R is as above.

Reacting the latter compound with N-bromo-succinimide forms l6fl-alkyl-9a-bromo-l1B,l7a,2l-trihydr0Xy-4 pregnene-3,20-dione ZI-acetate represented by the formula wherein R is as above.

Reacting the latter compound with sodium methoxide produces 16 8 alkyl 9B 1l/8-epoXy-l7a,2l-dihydroxy-4- pregnene-3,20-dione having the formula wherein R is as above.

The latter compound is acetylated with acetic anhydride in pyridine and then allowed to react with hydrogen flouride, to form 16fi-alkyl-9a-fluoro11fi,17a,21-trihydroxy-4-pregnene-3,20-dione 21-acetate of the following structural formula (IJH2OH CO (IJHQOAC C O wherein R is as above. The 21-acetate can be readily converted to the corresponding 21-01, namely, 16fl-alkyl-9afluoro 11,8,17oc,21 trihydroxy 4 pregnene 3,20- dione by hydrolysis. This latter compound may also be called 16fl-alkyl-9a-fluoro-hydrocortisone and it has been found that this compound is very effective in the treatment of arthritis.

In accordance with this invention, l6fi-alkyl-17a,21- dihydroxy ll oxygenated 1,4 pregnadiene 3,20- dione and l6fl-alkyl-9u-fiuoro-l7a,2l-dihydroxy-l l-oxygenated-1,4-pregnadiene-3,20-dione and the corresponding 21-acylates can be prepared by reacting respectively 16;?- alkyl 17a,21 dihydroxy 11 oxygenated pregnanc- 3,20-dione 2l-acetate and 16 -alky1-9u-fluoro-170,21-dihydroxy-ll-oxygenated pregnane-3,20-dione 2l-acetate with bromine to form the corresponding l6fi-alky1-2,4-

9 dibromo 17:1,21 dihydroxy 11 oxygenated pregnanc- 3,20-dione ZI-acetate which has the following structural formula:

CHzAc wherein R is as above and X is hydrogen or fluorine and R is hydroxy or oxygen.

Treatment of these species with dimethyl aniline in dimethylformamide results in the desired 16B-alkyl-17u,21- dihydroxy 11 oxygenated 1,4 pregnadiene 3,20- dione 21-acetate and 16 3-alkyl-9a-fluoro-17a,21-dihydroxy 11 oxygenated 1,4 pregnadiene 3,20 dione 21-acetate which may be represented graphically as follows CHzOAc wherein R, R" and X are as above. The species represented by the above formula are highly potent antiinfiammatory agents.

The 21-acetate esters of these compounds can be hydrolyzed to the corresponding alcohols, 16B-alkyl-17u,21-dihydroxy 11 oxygenated-1,4-pregnadiene-3,20-dione and 165-alkyl-9a-fluoro-17 a,21-dihydroxyl 11 oxygenated-1, 4-pregnadiene 3,20 dione represented by the following structural formula CHaOH CO Example 1.Preparation of 3a-acetoxy-16a,17umethyleneazo-pregnane-1 1,20-dione In a 500 ml. 3-neck flask equipped with condenser, dropping funnel and nitrogen inlet were placed 20 g. of potassium hydyroxide in 90 ml. of water, 100 m1. of methanol and 100 ml. of ether. A solution of g. of N-methyl- N-nitrosotosylamide in 50 ml. of ether was placed in the dropping funnel.

Diazomethane was generated by warming the generation flask to 40-45 C. and cautiously adding the N-methyl- N-nitrosotosylamide-ether from the dropping funnel. Nitrogen was utilized to sweep the diazomethane into a solution of 20 g. of 3a-acetoxy-16-pregnene-11,20-dione in ml. of tetrahydrofuran and ml. ether. The process was continued until the steroid solution remained yellow for several hours. The product, 3a-acetoxyl-16a, 17wmethyleneazo-pregnane-11,20-dione largely precipitated from the reaction mixture. After 16 hours, the mixture was filtered, washed with ether and dried in air. Yield 14.24 g., M.P. 186-190 C. (dec.) 2nd crop (on concentration) 4.45 g., M.P. 180-187 C., 3rd crop, 1.32 g., M.P. ISO-190 C. Total usable material 20.01 g. (90% LR. A359 5.78 sh, 5.82, 639p Nujol Analysis-Calculated for C H O N C, 69.55; H, 8.27. Found: C, 69,37; H, 8.01.

Example 2.Preparation of 3a-acetoxy- 16 -.methyl-16- pregnene-11,20dione; 3oz BCEtOXy-16oa,170L-I116thYl6116- pregnane-11,20-dione; 3a-acetoxy 16 methylenepregnane-11,20-dione and 3rx-hydroxy 16 methyl-16-pregnene-11,20-dione 37.4 g. of 3a-acetoxy 16a,17a methyleneazopregnane- 11,20-dione was placed in a 500 ml. round-bottom flask and heated by an oil bath in vacuo (pressure 0.6 mm.). A manometer and 12-liter surge flask were in the line between the reaction flask and pump trap. When the bath temperature reached 180 C. the 3a-acetoxy-16a,17amethyleneazopregnane 11,20 dione [began to melt with evolution of nitrogen. The maximum pressure reached was 83 mm. After 10 minutes at 180-182 C. the melt was cooled. It had onion max.

and was taken up in about ml. of acetone, filtered through diatomaceous earth, concentrated to about 100 ml. and ether slowly added to the boiling solution until crystallization occurred. These crystals of 3a-acetoxy-16- methyl 16 pregnene-11,20-dione weighed 19.0 g., M.P. 165-168 0.;

onion Ina)?- 2nd crop 5.3 g., M.P. -164 o.

ACHiOH 249, E% 211 max.

3rd crop 5.0 g., M.P. 142-153 C.,

AOHSOH 249, 1 3% 156 Example 3 .Preparation of 16oz, 17a-epoxy-3 ochydroxy-16fl-methylpregnaue-11,20-dione A solution of 20.0 g. of 3a acetoxy 16 methyl-16- pregnene-11,20-dione dissolved in 600 ml. of methanol, was cooled to 18 C., and 80 ml. of 30% hydrogen peroxide followed by 80 ml. of 2.5 N sodium hydroxide were added. Considerable material precipitated from solution, but all redissolved on stirring the reaction mixture at 25 30 C. for 40 minutes. The solution was kept at 15 20 C. for 18 hours at which time the ultra-violet maximum at 249 had completely disappeared. Then 600 ml. of saturated salt water was slowly added, the crystalline precipitate was filtered, washed with water, and dried in air and in vacuum. The 160,l7zx-6POXY-3a-llydI'OXy- 16/3-methylpregnane-11,20-dione thus formed weighed 17.36 g. (93%); M.P. 176l77 C., hexagonal prisms M.P. 178-180 C. from acetone-ether.

xOHCh 2.9-3.0, 5.86,.

max.

Analysis.-Calculated for C I-1 C, 73.30; H. 8.95. Found: C, 73.23; H, 9.12.

Room temperature acetylation gave the 3a-acetoxy- 16a,17a-epoxy-16B+methy-lpregnane-l1,20 having a melting point of 162l64 C.

Analysis.-Calculated for C H O C, 71.65; H, 8.51. Found: C, 71.65; H, 8.25.

Example 4.Preparation of an olefin mixture of 3a,17a-

dihydroxy 16 methyl pregnene-11,20-dione and 3 a,17i1-dihydroxy-16-methylenepregnane-1 1,20-dione To a solution of 2.69 g. of 16a,17u-epox-3a-hydroxy- 16/i-methyl-pregnane-11,20-dione in 55 ml. dioxane was added 27 ml. of 2 M aqueous perchloric acid. The clear solution was kept at -30 C. for 65 hours. Cold water, (175 ml.) was added, the slurry chilled to 8 C. and filtered after minutes. The precipitate, containing a mixture of 341,170: dihydroxy 16-methyl-15-pregnene- 11,20-dione and 3a,17a-dihydroxy-1G-methylene-pregnane was washed with water, and dried in air and finally at 50 C. in vacuum. Yield: 2.27 g. (94.5%), M.P. sintering at about 150 C. melting at 158167 C. The relative proportion of 3a,17a-dihydroxy-16-methyl-15-pregnene-11,20- dione and 3a,17a dihydroxy 16 methylenepregnane- 11,20-dione is estimated to be of the order of 1:1.

Example 5.Preparation of 3a,11B-dihydroxy-16-methyl- 15 etiocholene 17 one and 342,115 dihydroxy 16- methylene-etiocholane-17-one Treatment of the mixture of 3oz,l7u-dihyd1OXY-l6- methyl-15-pregnene-11,20-dione and 3a,17a-dihydroxy- 16 methylene pregnane-11,20-dione successively with lithium aluminum hydride and sodium periodate gave a crystalline mixture (M.P. 166-171 C.) of endocyclic 30;,11/3 dihydroxy 16 methyl 15 etiocholene 17- one and exocyclic 311,115 dihydroxy 16 methylene etiocholane-17-one C-17 ketones with The conjugate C=O peaks at 5.80 and 5.87 were of equal intensity indicating the proportions to be 1:1.

Pure 3a,11fi dihydroxy-16-methylene-etiocholane-17- one (11.1 715 51 227, 13% 270; xggf 2.75, 2.82-2.92, 5.79,

Example 6.-Preparation of 3a-acetxoy-17a-hydroxy-16- methylene-pregnane-l1,20-dione and 3a-acetoxy-15- bromo-16-methyl-16'pregnene-11,20-dione IBEX.

Analysis.Calculated for C H O Br: C, 61.93; H, 7.14; Br, 17.17. Found: C, 61.83; H, 6.99; Br, 16.89.

From the 50:50 petroleum ether-benzene to benzene eluates there was obtained 1.60 g. 3oc-acetoxy- 17a-hydroxy-16-methylene-pregnane-11,20-dione; prisms from acetone-ether M.P. 198-200 C. [a] 5.2 (C=1.00)

Analysis.Calculated for C H O C, 71.64; H, 8.51. Found: C, 71.51; H, 8.07.

Example 7.-Preparation of 3a-acetoxy-16-methyl-l4,16- pregnadiene-11,20-dione 42 mg. of 3o-acetoxy-15-bromo-16-methyl-16-pregnene- 11,20-dione was dissolved in 2 ml. of pyridine. After 18 hours at 25 C. the mixture was concentrated to dryness in vacuo. The solid residue of 3a-acetoxy-16-methyl- 14,16-pregnadiene-11,20-dione was crystallized from ether; prismatic needles M.P. 180185 C;

Example 8 A solution of 3.05 g. (8.47 millimol) of the olefin mixture of 301,170: dihydroxy 16-methyl 15 pregnene- 11,20-dione and 3a,17a-dihydroxy-16-methylene-pregnane- 11,20-dione in 80 ml. of methanol was reduced in hydrogen at 1 atmosphere and 25 C. in the presence of 2.0 g. of 25% palladium-calcium carbonate catalyst. Modification of the hydrogenation conditions, pH, solvent, catalyst, etc. alters the isomer ratio significantly. Uptake of the calculated amount of hydrogen was complete in 45 minutes. The mixture was stirred an additional 30 minutes and fiiltered through diatomaceous earth. The colorless filtrate was taken to dryness and crystallized from ether: a mixture of 3a,17a-dihydroxy-16u-methylpregnane-11,20-dione and 3a,17a-dihydroxy-16fi-methy1- pregnane-11,20-dione was obtained and weighed 3.05 g., sintering at C. melting at 166-182 C.

The product consists of 3a,17a-dihydroxy-16ot-methylpregnane-11,20-dione and 3a,17a-dihydroxy-16,8-methylpregnane-11,20-dione in the ratio ca. 7:3 as determined by the amounts of end product isolated below.

Example 9.Alternate preparation of 3a,17u-dihydroxy- 16a methylpregnane 11,20 dione and 3a,17o-dihydroxy-l 6,8-methylpregnane-1 1,20-dione palladium on charcoal catalyst. Uptake of one mole of hydrogen was complete in 10 hours. The catalyst was removed by filtration and 300 ml. of 70% saturated sodium chloride was added to the filtrate. After being kept at C. for 30 minutes, the precipitated mixture of 30:,17adihydroxy-l6a-methylpregnane-l1,20-dione and 3:1,1711- dihydroxy-lfi-methylpregnane-l1,20-dione was filtered, washed with water and dried in air. Yield: 9.26 g. Solubility analysis in benzene indicated the product to be 75% 3a,17a-dihydroxy-16u-methylpregnane-l1,20-dione and 25% 3a,17oc-dihydroxy-16[3 methylpregnane-11,20- dione.

Example 10.4eparation of 3a,17a-dihydroxy-16umethylpregnane 11,20 dione and 3u,l7a-dil1ydroxy- 1 613-methylpregnane-1 1,20-dione One gram of the above hydrogenation product, 311,170:- dihydroxy-locc-methylpregnane-l1,20-dione and 311,170:- dihydroxy-l6fi-methylpregnane-l1,20-dione, was chromatographed on 100 g. of activated magnesium silicate. The 100% chloroform eluates gave 3a,l7a-dihydroxy- 1a-methylpregnane-l1,20-dione, M.P. 188191 C. identical with authentic material by mixed melting point and infrared spectral comparisons. The 5% methanolchloroform eluates gave 3a,I7u-(lihyChOXY-16B-H16thYlpregnane-11,20-dione hexagonal plates from benzeneethylacetate M.P. 192197 C.;

as? 2.90-3.05, ass-5.90..

AnaZysis.Calculated for C H O C, 72.89; H, 9.45. Found: C, 72.97; H, 9.25.

The 16a-met-hyl and lp-methylpregnanes respectively, had R values of 0.55 and 0.35 when chromatographed on Whatman #1 filter paper in the benzene-formamide system.

As described hereinafter, 3a,17a-dihydoxy-16fi-methylpregnane-l1,20-dione was brominated at position 21 in exactly the same Way as the mixture of 16a and 16B- methyl compounds to give 21-bromo-3u,17a-dihydroxy- 16,8-methylpregnane-11,20dione. This latter compound was similarly converted to 3a-17a,21-trihydroxy-16/3- methylpregnane-l1,20-dione 21-acetate. This compound was then similarly oxidized at position 3 to give 17a,21 dihydroxy-165-methyl-3, l l,20-trione 21-acetate.

Example 1l.Preparation of a mixture of 3a-acetoxy- 17a-hydroxy-16a-rnethyl-pregnane-11,20-dione and 30aacetoxy-17a-hydroxy-1SB-methylpregnane-l 1,20-dione To a mixture of 3a,17u-dihydroxy-16m-methylpregn'ane- 11,20-dione and 3a,17a-dihydroxy-16B-methylpregnane- 11,20-dione dissolved in pyridine was added acetic anhydride at 20 C. A mixture of 3a-E1C6EOXY-17a-hYd1'OXY- 16u-methylpregnane-11,20-dione and 3a-acetoxy-17a-hydroxy-IGB-methyIpregnane-l1,20-dione separated from solution and was recovered. These prisms sintered at 170 C. and melted at 170179 C.

Example 12.-Preparation of a mixture of 21-bIOII10-3oc, l7a'dihydroxy-1Sa-methylpregnane 11,20 dione and 2l-bromo-3a,17u-dihydroxy-165-methylpregnane 11, 20'dione A solution of 3.50 g. (9.7 millimol) of a mixture of 3a,17u-dihydroxy-1fia-methylpregnane-l1,20 dione and 3a,17a-dihydroxy-16fi-methylpregnane-11,20 dione obtained as above in 40 ml. of chloroform was warmed to 4045 C. A solution of 1.76 g. (11 millirnol) of bromide in 25 ml. of chloroform was added dropwise to the stirred solution such that the color was not darker than pale yellow (ca. 2 drops/sec., total time-1 hour). The nearly colorless solution was cooled to 20 C. and 200 ml. of ether was added. The mixture was extracted with excess cold 5% potassium bicarbonate solution, sodium bisulfate solution, and water and dried over magnesium sulfate. The colorless residue after removal of solvent, a mixture of 21-bromo-3a,17a-dihydroxy-lfia-methylpregnane-11,20-dione and 21-bromo-3u,17ot-dihydroxy- 165-methylpregnane-11,20-dione (4.30 g.) gave a positive tetrazolium test. Paper chromatography (benezeneformamide) resolved the material into 2 spots.

Example 13.Prepar-ation of a mixture of 3u,17a-2l-trihydroxy-l6u-methylpregnane-11,20-dione 21 acetate and 3a,17a,2l-trihydroxy-lfifi-rnethylpregnane 11,20 dione 21-acetate To 4.30 g. of 21-bromo-3a,17a-dihydroxy-16a-methylpregnane-11,20-dione and 21-bromo-3a,17adihydroxy- 16(3-methylpregnane-11,20-dione in ml. of acetone and 0.10 ml. acetic acid were added 4.83 g. of anhydrous potassium acetate and 3.85 g. of potassium iodide. The stirred mixture was refluxed for 18 hours and concentrated on the water pump to a small volume. Water was added, the product extracted into ethyl acetate, and the organic extract dried over magnesium sulfate. The product (4.25 g.) was a colorless foam that partly crystallized from acetone-ether to give ca. 30% dense cubes sintering at about 150 C., and melting at 200213 C., which paper chromatography showed was mainly 3a,17a,21-trlhydroxy-l6B-methy1pregnane-l1,20-dione 21-acetate contaminated with some 3a,17a,2l-trihydroxy-lM-methylpregnane-11,20-dione 21-acetate. The IR. spectrum of this material was similar to that of authentic 3a,l7u,2ltrihydroxy-16a-methylpregnane-11,20-dione 21-acetate in the functional group region but differed significantly in the fingerprint region. Seeding the mother liquors with anthentic 3a,l7a,2l-trihydroxy-l6a-rnethylpregnane 11,20- dione 21-acetate induced crystallization of crude 3a,17a, 2l-hydroxy-16a-methylpregnane-11-20-dione 21 acetate which was purified by repeated crystallization from acetone-ether and shown to be identical with an authentic sample by mixed M.P., LR. and paper chromatographic comparisons.

Example 14.Preparation of 17a,2l-dihydr0xy-16amethylpregnane-3,l1,20-trione 21-acetate and 170:,21- dihydroxy-l6B-methylpregnane-3,l1,20-trione 21 acetate To the mixture obtained as above of 3a,17a,21-trihydroxy-l6a-methylpregnane-l1,20-dione 21-acetate and 3a,17a,21-trihydroxy-l6fi-methylpregnane-11,20-dione 21- acetate, 40 g., in ml. t-butanol and 20 m1. of water cooled to 10-15 C., was added 3.5 g. N-bromo-succinimide. The suspension was stirred at 15 C. until all the N-bromosuccinimide had dissolved (90 minutes). The reaction mixture was kept at 2 C. for about sixteen hours and at 25 C. for 2 hours. Sodium sulfite solution was added to destroy bromine and the mixture concentrated on the water pump to a low volume. A granular precipitate had formed; water was added, the precipitate filtered and washed with water: 3:30 g., sintering at about 170 C. melting at about 202-212 C. Extraction of the filtrate with ethyl acetate gave .3 50 g., M.P. C. Since both samples were mixtures by paper chromatography, they were recombined for alumina chromatography. Trituration with 100 ml. hot benzene gave 540 mg. of material M.P. 225 235 C. Chromatography of the remainder on neutral alumina (85 g., 100 ml. fractions) gave 1.324 g. of 17a,2l-dihydroxy-l6amethylpregnane-3,11,20-trione 21-acetate, M.P. 230 C. from fractions 5-15; (5% CHCl -70% C H Fractions 17-21 (50% CHCl -50% C l-I to 100% CHCl contained 0.850 g. 17a,21-dihydroxy-16B-methylpregnane-3, 11,20-trione 21-acetate, M.P. 210213 C. The yield was about 2.0 g. [1.87 g.+ca. .10.20 g. in mixed fraction 16]. The ratio of 17a,21-dihydroxy-16a-methylpregnane-3,11, 20-trione 21-acetate to 17a,21-dihydroxy-16,8-methylpregnane-3,l1,20-trione ll-acetate, 2.0:O.85=7:3, is probably close to the ratio of 3a,17u-dihydroxy-16umethylpregnane-11,20-dione produced in the hydrogenation.

Pure 17u,21-dihydroxy-16B-methylpregnane 3,11,20

trione 21-acetate had the following properties: M.P. 210- 212 C.

Analysis.--Calculated for C H O C, 68.88; H, 8.19. Found: C, 68.81; H. 7.91.

Example l5.Preparation of 4-bro mo-17a,21-dihydroxy-165-methylpregnane-3 ,1 1,20-trione 2 l-acetate To a stirred solution of 585 mg. of 17a,2l-dihydroxy- 16,8-methylpregnaue-3,11,20-trione 21-acetate in ml. of acetic acid and 8 ml. of chloroform kept at -10 C. was added slowly 230 mg. of bromide in 6 ml. of chloroform. After addition was complete, 1.2 g. of sodium acetate in 7 ml. of cold water was added. Additional water was added and the mixture was extracted with chloroform. The chloroform extract was washed with dilute potassium bicarbonate, water and dried over sodium sulfate. The residue was triturated with ether to give 480 mg. of crystalline 4-bromo-17a,21-dihydroxy-16fl-methylpregnane-3,11,20-trione 21-acetate M.P. 165-170 C. dec.

Analysis.-Calculated for C H O Br: Found: Br, 15.58.

A second crop of 133 mg. of 4-bromo-17a,21-dihydroxy-l6fi-methylpregnane-3,l1,20-trione Zl-acetate was also obtained.

Example 16.Preparation of the 3-semicarbazone of 17a,21-dihydroxy-l6B-methyl-4-pregnene-3,1 1,20-trione ZI-acetate To 583 mg. of 4-bromo-l7a,21-dihydroxy-16fi-methylpregnane-3,1l,20-trione 21-acetate in 20 ml. of acetonitrile under nitrogen was added a slurry of 600 mg. of semicarbazide hydrochloride and 410 mg. sodium bicarbonate in 4 ml. of Water. After 2 hours, the acetonitrile was removed in vacuo, water added and 540 mg. of crystalline 3-semicarbazone of 17u,21-dihydroxyl-16fi-methyl- 4-pregnene-3,11,20-tri0ne 21-acetate filtered, washed with Water and dried.

Example 17.Preparation of 17a,21-dihydroxy-l6fimethyl-4-pregnene-3,11,20-trione ZI-acetate 540 mg. of the semicarbazone of 17a,21-dihydroxyl6B-methyl-4-pregnene-3,l1,20-trione ZI-acetate was dissolved in 20 ml. of acetic acid, 1.5 ml. of pyruvic acid and 5 ml. of water. After 18 hours at 25 C., Water was added and the mixture extracted with chloroform. The chloroform extract was washed with aqueous potassium bicarbonate, water and dried over soduim sulfate. Removal of solvent gave crude 17a,2l-dihydroxy-16fi-methyl-4- pregnene-3,11,20-trione 21-acetate which was purified by chromatography on neutral alumina and crystallization from acetone-ether (hexagonal plates). The pure material had M.P. 226232 C.

238 mu E: 15,600;

Analysis.-Calculated for G l-1 0 C, 69.21; H, 7.75. Found: C, 69.24; H, 7.58.

Example 18.Preparation of the 3,20-disemicarbazone of 17a,21-dihydroxy-l6p-methy1-4-pregnene-3, l 1,20-trione 21-acetate To a stirred solution of 500 mg. of 17a,2l-dihydroxy- 16,9-methyl-4-pregnene-3J1,20 trione 21 acetate (prepared as described in Example 17) in 12.5 ml. of methanol and 3 ml. of dimethylformamide kept under nitrogen was added a slurry of 680 mg. of semicarbazide hydrochloride and 370 mg. of sodium bicarbonate in 1 ml. of water. The stirred mixture was refluxed 3V2 hours and maintained at 45 C. for 17 hours. It was then cooled to 20 C. and 50 ml. of 50% saturated aqueous sodium chloride was added. After 2 hours at 0 C, the precipitate of the 3,20-disemicarbazidone of l7a,21-dihydroxy-16,8-methyl-4-pregnene- 3,11,20-trione 21-acetate was filtered, washed with water until free of chloride ion and dried in air. Yield over Example l9.Preparation of the 3,20-disemicarbazone of 1 1,8, 17042l-trihydroxy-16,8-methyl-4-pregnene-3,ZO-dione To a stirred solution of 600 mg. of the 3,20-disemicarbazone of 17a,2l-dihydroxy-16B methyl-4-pregnene-3,11, 20-trione 21-acetate in 30 ml. of tetrahydrofuran and 11 ml. of water under nitrogen was added 200 mg. powdered sodium borohydride. The stirred suspension was refluxed 45 minutes and then cooled to 15 C. Aqueous acetic acid (3 ml. of 30%) was added cautiously and most of the tetrahydrofuran was removed in vacuum. Addition of 5 ml. of methanol and 5 ml. of water induced the product to crystallize. Following addition of 10 ml. of a saturated sodium chloride solution and aging at 0 C. the product 3,20 disemicarbazone of 11,8,17a,21 trihydroxy 165- methyl-4-pregnene-3,20-dione was filtered, Washed with water, and dried in air.

Example 20.Preparation of 1l5,17a,2l-trihydroxy-l6flmethyl-4-preguene-3,20-dione To a solution of 510 mg. of reduced 3,20-disemicarbazone of 11B,17a,21-trihydroxy-16B-methyl-4-pregnene- 3,20-dione in 5 ml. of acetic acid was added 1.20 ml. of water and 0.50 ml. of pyruvic acid. The solution was kept at 25 C. for eighteen hours. Water (20 ml.) was added, and the mixture was extracted thoroughly with chloroform. The chloroform extract was dried over magnesium sulfate and taken to dryness. The residue was crystallized from acetone-ether to give pure llfi,l7a,2ltrihydroxy- 16fl-methyl-4-pregnene-3,20-dione.

Example 2l.-Preparation of 11/8,17ot,21-trihydroxy-16flmethyl-4-pregnene-3,ZO-dione 2l-acetate The product of the previous Example 20 was acetylated at C-21 as follows: A solution of mg. of 11[3,17a,21- trihydroxy-l6fl-methyl-4-pregnene-3,20-dione in 100 ml. of pyridine and 0.5 ml. of acetic anhydride was prepared. After 18 hours at 25 C., the solution was taken to dryness in vacuo and the solid residue purified by crystallization in acetone-ether to give 11B,1702,21-tfil1Yd1OXY-16B- methyl-4-pregnene-3,20-dione 21-acetate.

Example 22.Preparation of l 7a,21-dihydroxy-1 6 8- methyl-4,9 1 l -pregnadiene-3 ,20-dione 2 l -acetate Example 23.-Preparation of 9a-bromo-1l,B,l7u,2l-trihydroxy-16/3-methyl-4-1pregnene-3,20-dione 21-acetate To a mixture of 620 mg. of 17a,21-dihydroxy-16B- methyl-4,9(11)-pregnadiene-3,20-dione 21-acetate and 330 mg. of N-bromosuccinimide in 10 ml. of dioxane and 3.2 ml. of water cooled to 10 C. was added 1.8 ml. 'of cold 1 M aqueous perchloric acid. The mixture was stirred at 15 C. for 3 hours. Excess N-bromosuccinimide was destroyed by addition of aqueous sodium thiosulfate and most of the dioxane was removed in vacuo. About 30 ml. of water was added and crystalline bromohydrin, 9abromo-l1B,17a21-trihydroxy 16,8 methyl 4 pregnene- 17 3,20-dione 21-acetate, was filtered, washed with water, and dried in air.

Example 24.-Preparation of 9,9,11 8-epoxy-17a,21-dihydroxy-16,6-methyl-4-pregnene-3,20-dione 21-acetate To a stirred solution of 100 mg. of the 9u-bromo-11p, 170:,21-trihydroxy-16B-methyl-4-pregnene-3,20 dione 21- acetate in 3 ml. of tetrahydrofuran and 1 ml. of methanol under nitrogen was added 1.02 ml. of 0.215 N methanolic sodium methoxide. After 10 minutes at 25 C. 0.2 ml. of acetic acid was added and the methanol removed in vacuo. The residue was acetylated with 1.00 ml. of pyridine and 0.5 ml. of acetic anhydride at 60 C. for 70 minutes. The mixture was taken to dryness in vacuo, water added, and the product extracted into chloroform. The residue was crystallized from ether-acetone to give pure 95,11,6- epoxy-1711,2l-dihydroxy-16 9-methyl-4-pregnene-3,20 dione 21-acetate.

Example 25.--Preparation of 9mfiUOIO11B,17cc-trihydroxy-l 6fi-methyl-4-pregnene-3 ,20-dione 21-acetate To a solution of 200 mg. of 9B,11;3-epoxy-17a,21-dihydroxy-l6fl-methyl-4-pregnene-3,ZO-dione 21-acetate in 2 ml. of chloroform and 2 ml. of tetrahydrofuran in a polyethylene bottle at 60 C. was added 2 ml. of a 2:1 (by weight) mixture of anhydrous hydrogen fluoride and tetrahydrofuran. After 4 hours at -10 C. the mixture was cooled to 60 C. and cautiously added to a stirred mixture of 30 ml. of 25% aqueous potassium carbonate and 25 ml. of chloroform kept at -5 C. The aqueous phase was further extracted with chloroform and the latter phase washed with water and dried over magnesium sulfate. The residue on crystallization from acetone-ether gave pure 9a-fluoro-l 1,3,17a,21-trihydroxy-16/3-methyl-4-pregnene-3,20-dione 21-acetate.

Example 26.Preparation of 9a-fluoro-11fi,l7a,21-trihydroxy-l6,8-methyl-4-pregnene-3,20-dione To a stirred solution of 110 mg. of 9oz-fll1010-11B,17a, 21-trihydroxy-16fi-methyl-4-pregneue-3,20-dione 21-acetate in 5 ml. of methanol under nitrogen at 25 C. was added 1.00 ml. of 0.26 M methanolic sodium methoxide. After 15 minutes 0.2 ml. of acetic acid in 1 ml. of water was added and the mixture concentrated nearly to dryness. The residue was taken up in ethyl acetate and the ethyl acetate solution was washed with water, dried over magnesium sulfate, and concentrated to dryness. Crystallization of the residue from ethyl acetate gave pure 9a-fluoro- 1113,17 x,21trihydroxy-16p-methyl-4-pregnene-3,20-dione.

Example 27.Preparation of 9a-chloro-11;9,17a,21-trihydroxy-16fl-methyl-4-pregnene-3,20-dione 21-acetate To a solution of 100 mg. of 9,9,11B-epoxy-17a,21-dihydroxy-l6B-methyl-4-pregnene-3,20-dione 21-acetate in 4 ml. of chloroform was added 5 ml. of concentrated hydrochloric acid. The two-phase mixture was stirred at 25 C. for 1 hour. Addition of water and chloroform extraction gave a crude crystalline product which is partly deacetylated. Treatment with 1 ml. of pyridine and 0.5 ml. of acetic anhydride at 25 C. for 18 hours followed by concentrations in vacuo and crystallization of the residue from acetone-ether afforded pure 9oc-Cl1lOIO-11fl,17m, 21-trihydroxy-16fi-methyl-4-pregnene-3,204'1ione 21-acetate.

Example 28.Preparation of 2,4-dibromo-17a,21-dihydroxy- 1 Gfi-methyl-pre guano-3 ,1 1,20-trione 21-acetate To a stirred solution of 682 mg. of 17a,21-dihydroxy- 16fl-methylpregnane-3J1,20-trione 21-acetate (prepared as described in Example 17) in 20 ml. of chloroform and 2.25 ml. of acetic acid maintained at 20 C. was added dropwise one-half of a solution of 540 mg. of bromine in 2 ml. of chloroform and 3 ml. of acetic acid. The mixture was warmed to 0 C. and the remainder of the bromine added. Sodium acetate (0.4 g.) in 2 ml. of water was added followed by 20 mg. of sodium sulfite. The

18 mixture was concentrated in vacuo to remove the chloroform and 20 ml. of water was added. The white powdery precipitate of 2,4-dibromo-17a,21-dihydroxy-16B-methylpregnane-3,11,20-trione ZI-acetate was filtered, washed with water and dried in air. Yield: 920 mg. M.P. 122- C. dec.

Example 29.-Preparation of 17a,21-dihydroxy-16;3- methyl-1,4-pregnadiene-3,11,20-trione 21-acetate igg 238 m (E: 15,300 x 2.9-3.0, 5.75, 5.79, 5.84, 6.01, 6.16, 6.19, 11.20,.

Analysis.-Calculated for C H O C, 69.55; H, 7.30. Found: C, 69.25; H, 7.25.

Example .30.Preparation of 17a,21-dihydroxy-l6flmethyl-1,4-pregnadiene-3 ,1 1,20-trione This compound was obtained by treatment of 1.0 g. of 17,21 dihydroxy 16,6-methyl-l,4-pregnadiene-3,11,20- trione 21-acetate in 30 ml. of methanol with 1 g. of potassium bicarbonate in 10 ml. of water under nitrogen at reflux temperature for 7 minutes. The mixture was cooled, neutralized with 1 ml. of acetic acid in 10 ml. of water, the methanol removed in vacuo and the product extracted into ethyl acetate. Removal of the ethyl acetate gave crystals (900 mg.) M.P. -200 of the desired 1711,21- dihydroxy-l 6fl-methyl-1,4-pregnadiene-3 ,11,20-trione.

Example 3l.-Preparation of 11fi,17a,21-trihydroxy-l6/8- methyl-1,4-pregnadiene-3,20-dione 21 acetate To 100 mg. of 11B,17a,2l-trihydroxy-16fi-methyl-4- pregnene-3,20-dione 21-acetate in 5 ml. of t-butanol and 0.1 m1. of acetic acid was added 50 mg. of selenium dioxide. The mixture was refluxed under nitrogen 18 hours, 50 mg. of selenium dioxide was added and the mixture refluxed an additional 24 hours. Themixture was filtered, and the filtrate taken to dryness. The residue was taken up in ethyl acetate and washed successively with aqueous sodium bicarbonate, ammonium sulfide, dilute ammonia water, water, dilute hydrochloric acid and water and dried over magnesium sulfate. It was then treated with activated charcoal and concentrated to dryness. Crystallization of the residue from acetone-ether gave pure 11B,17a,21-t1'ihydroxy 16 3 methyl l,4-pregnadiene-3,20-dione 21- acetate.

Example 32 Alternately, the 1,2dehydrogenation of 11/3,l7a,21-trihydroxy-16,3-methyl-4-pregnene-3,20-dione 21-acetate can be carried out microbiologically by means of Bacillus sphaericzls to yield 11,8,17a,2ltrihydroxy-16fi-methyl-1,4- pregnadiene-3,20-dione, which on acetylation with acetic anhydride pyridine gives 11B,17a,21 trihydroxy 16emethyl-l,4-pregnadiene-3,20-dione 21-acetate.

Example 33.Preparation of 9a-fiuoro-11B,l7a,21-trihydroxy-l 6B-methyl-1,4-pregnadiene-3 ,20-dione 21-acetate In a similar manner, 100 mg. of 9oc-fi110rO-11/3,l7a,2l trihydroxy-16fi-rnethyl-4-pregnene-3,20-di0ne 21-acetate was treated with selenium dioxide to produce the corresponding 9a-fluoro-11,3,17a,21-trihydroxy-16,B-methyl-1,4-

pregnadiene-3,20,-dione 21-acetate. Alternately, Bacillus sphaericus may be utilized. The 21-alcohol was prepared from the 21-acetate as in Example 26 or Example 30.

Various changes and modifications may be made in the present invention, certain preferred embodiments of which are herein disclosed, without departing from the scope thereof; to the extent that these changes and modifications are Within the scope of the appended claim, which is to be considered a part of this invention.

We claim:

1. The process which comprises reacting 3oc-IOW6I alkanoyloXy-16-lower alkylenepregnane-l1,20-dione with methanolic potassium hydroxide to form 16-lower alkyl- 3a-hydroxy 16-pregnene-1 1,20-dione.

References Cited UNITED STATES PATENTS 2,705,233 3/1955 Julian 26%23955 OTHER REFERENCES Marker et al., J.A.C.S. 64, 1280 (1942). 

1. THE PROCESS WHICH COMPRISES REACTING 3A-LOWER ALKANLYLOXY-16-LOWER ALKYLENEPREGNANE-11, 20-DIONE WITH METHANOLIC POTASSIUM HYDROXIDE TO FORM 16-LOWER ALKYL3A-HYDROXY-16-PREGNENE-11, 20-DIONE. 